DIOPSIDE  , an important member of the See also:

• PYROXENE

pyroxene See also:

• GROUP

group of See also:

• ROCK
• ROCK (O.Fr. rake, Sp. rota, Ital. rocca; possibly from a Lat. form rupica, from rupes, rock)
• ROCK, DANIEL (1799–187t)

rock-forming minerals . It is a See also:

• CALCIUM [symbol Ca, atomic weight 40.0 (o= x6)]

calcium-See also:

• MAGNESIUM [symbol Mg, atomic weight 24.32 (0 = 16)]

magnesium metasilicate, CaMg (SiO3)2, and crystallizes in the See also:

• MONOCLINIC

monoclinic See also:

• SYSTEM

system . Usually some See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron is See also:

• PRESENT

present replacing magnesium, and when this pre-dominates there is a passage to hedenbergite, CaFe(SiO3)2, a closely allied variety of monoclinic pyroxene . These are distinguished from See also:

• AUGITE

augite by containing little or no See also:

• ALUMINIUM (symbol Al; atomic weight 27.0)

aluminium . Diopside is colourless, See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white, See also:

• PALE (through Fr. pal, from Lat. palms, a stake, for paglus, from the stem pag- of pangere, to fix; " pole " is from the same original source)

pale See also:

• GREEN, A
• GREEN, ALEXANDER HENRY (1832—1896)
• GREEN, DUFF (1791—1875)
• GREEN, JOHN RICHARD (1837—1883)
• GREEN, MATTHEW (1696-1737)
• GREEN, THOMAS HILL (1836-1882)
• GREEN, VALENTINE (1739–1813)
• GREEN, WILLIAM HENRY (.1825–1900)

green to dark green or nearly See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black in See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour, the See also:

• DEPTH

depth of the colour depending on the amount of iron present . The specific gravity and See also:

• OPTICAL

optical constants also vary with the chemical See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition; the sp. gr. of diopside is 3.2, increasing to 3.6 in hedenbergite, and the See also:

• ANGLE (from the Lat. angulus, a corner, a diminutive, of which the primitive form, angus, does not occur in Latin; cognate are the Lat. angere, to compress into a bend or to strangle, and the Gr. ayKOS, a bend; both connected with the Aryan root ank-, to

angle of optical extinction in the See also:

• PLANE

plane of symmetry varies between 38° and 47° in the two extremes of the See also:

• SERIES (a Latin word from serere, to join)

series, Crystals are usually prismatic in See also:

• HABIT (through the French from Lat. habitus, from habere, to have, hold, or, in a reflective sense, to be in a certain condition; in many of the English senses the French use habitude, not habit)

habit with a rectangular See also:

• CROSS

cross-See also:

• SECTION
• SECTION (Lat. sectio, cutting, secare, to cut)

section as shown in the figure: the angle between the See also:

• PRISM (Gr. rrpivµa, properly a thing sawn, Irpii"ety, to saw)

prism faces m, parallel to which there are perfect cleavages, is 92° 50' . Several varieties, depending on See also:

• DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences in structure and chemical composition, have been distinguished, viz. coccolite (from KoKKOS, a See also:

• GRAIN (derived through the French from Lat. granum, seed, from an Aryan root meaning " to wear down," which also appears in the common Teutonic word " corn ")

grain), a granular variety; salite or sahlite, from See also:

• SALA, GEORGE AUGUSTUS HENRY (1828-1895)

Sala in See also:

• SWEDEN
• SWEDEN [Sverige]
• SWEDEN, NORWAY AND

Sweden; malacolite; See also:

• DIALLAGE

diallage; violane, a lamellar variety of a dark See also:

• VIOLET

violet-See also:

• BLUE (common in different forms to most European languages)

blue colour; chrome-diopside, a See also:

• BRIGHT, JOHN (1811-188g)
• BRIGHT, SIR CHARLES TILSTON

bright green variety containing a small amount of See also:

• CHROMIUM (symbol Cr. atomic weight 52.1)

chromium; and many others . Belonging to the same series with diopside and hedenbergite is a See also:

• MANGANESE (symbol Mn; atomic weight, 54.93 (0=16)], a metallic chemical element. Its dioxide (pyrolusite)

manganese pyroxene, known as schefierite, which has the composition (Ca, Mg) (Fe, Mn) (SiO3)2 . Diopside is the characteristic pyroxene of metamorphic rocks, occurring especially in crystalline limestones, and often in association with See also:

• GARNET
• GARNET, or GARNETT, HENRY (1555—1606)

garnet and See also:

• EPIDOTE

epidote . It is also an essential constituent of some pyroxene-granites, diorites and a few other igneous rocks, but the characteristic pyroxene of this class of rocks is augite . See also:

• FINE

Fine transparent crystals of a pale green colour occur, with crystals of yellowish-red garnet (hessonite) and See also:

• CHLORITE

chlorite, in See also:

• VEINS

veins traversing See also:

• SERPENTINE

serpentine in the See also:

• ALA

Ala valley near See also:

• TURIN

Turin in See also:

• PIEDMONT (Ital. Piemonte; Low Lat. Pedemons and Pedemontium)

Piedmont: a crystal of this variety (" alalite ") is represented in the accompanying figure . These, as well as the See also:

• LONG, GEORGE (1800-1879)
• LONG, JOHN DAVIS (1838– )

long, transparent, See also:

• BOTTLE (Fr. bouteille, from a diminutive of the Lat. butta, a flask; cf. Eng. " butt ")

bottle-green crystals from the Zillerthal in the Tyrol, have occasionally been cut as See also:

• GEM (Lat. gemma, a bud,—from the root gen, meaning " to produce,"—or precious stone; in the latter sense the Greek term is > d>os)
• GEM, ARTIFICIAL

gem-stones .

See also:

• GOOD, JOHN MASON (1764-1827)

Good crystals have been found also at Achmatovsk near See also:

• ZLATOUST

Zlatoust in the Urals, Traversella near See also:

• IVREA (anc. Eporedia)

Ivrea in Piedmont (" traversellite "), Nordmark in Sweden, See also:

• MONROE
• MONROE, JAMES (1758-1831)

Monroe in New See also:

• YORK
• YORK (HOUSE OF)
• YORK, EDMUND OF LANGLEY, DUKE OF (1341-1402)
• YORK, EDWARD
• YORK, FREDERICK AUGUSTUS, DUKE OF (1763-1827)
• YORK, RICHARD, DUKE

York, See also:

• BURGESS (Med. Lat. burgensis, from burgus, a borough, a town)
• BURGESS, DANIEL (1645-1713)
• BURGESS, THOMAS (1756–1837)

Burgess in See also:

• LANARK

Lanark See also:

• COUNTY (through Norm. Fr. comae, cf. O. Fr. cunte, conk', Mod. Fr. comae, from Lat. comitatus, cf. Ital. comitato, Prov. comtat; see COUNT)

county, See also:

• ONTARIO
• ONTARIO, LAKE

Ontario, and several other places: at Nordmark the large, rectangular black crystals occur with See also:

• MAGNETITE

magnetite in the iron mines . (L . J .